Thursday, August 21, 2014

A Serendipitous Stereographic Projection

Serendipity uses data from Spotify to show you the locations of two Spotify users who are listening to the same track at the same time. The map shows the locations of two users who have started listening to the same song on Spotify within a tenth of a second of each other, in different towns, cities, states, nations or timezones.

The thing I most like about this application is the use of a stereographic projection. The Web Mercator projection seems to rule the roost in online mapping these days, so it is nice to see a different map projection get a rare outing.

When the map progresses from one paired serendipitous song to the next couple of users it animates to a new map view, which is particular interesting to watch with this stereographic projection. You also get a quick blast of each new song featured as the map animates around the world.

The map was created with the help of D3.js. If you want to use a stereographic projection in your own maps you can check out the D3.js code for this map projection and a demo stereographic projection map here.